With the development of human-computer interaction technology, touch technology is increasingly used in a variety of displays. Capacitive touch technology is widely used due to its advantages of wear resistance, long service life, low maintenance cost for user, and capability of supporting gesture recognition and multi-touch.
Capacitive touch technology can be divided into self-capacitance touch technology and mutual capacitance touch technology depending on the detection method of capacitance between objects. Through the self-capacitance touch technology, presence, location and movement of an input object on a touch screen is detected according to change in capacitance between an electrode and the ground caused by the input object. Through the mutual capacitance touch technology, presence, location and movement of an input object on a touch screen is detected according to change in capacitance between electrodes caused by the input object. Compared with the mutual capacitance touch technology, the self-capacitance touch technology has advantages such as low cost, high report rate and excellent hovering characteristic.
In addition, depending on the location of the touch panel in the display device, touch display devices can also be divided into in-cell touch display devices, on-cell touch display devices and out hanging touch display devices. The in-cell touch display device has become an important research direction of the touch technology due to its advantages of high integration, low profile and superior performance, etc.
In the in-cell self-capacitance touch technology of the prior at, for example, a common electrode layer on an array substrate is reused as a touch electrode, and the touch electrode is connected to a driving circuit of the array substrate by a touch line. In order to reduce the load of the array substrate, generally a touch line which is broken into segments is used to connect the touch electrode and the driving circuit of the array substrate. However, as shown in FIG. 1, since the touch line 110 is of a broken type, via holes 130 are provided in the region 121 of the touch electrodes 120, and no via hole is provided in another region 122. Then, there is a large difference in the amount of via holes between the region 121 and the region 122. This causes the via holes 130 unevenly distributed on the touch electrodes 120, and brings about problems such as unevenness and visible mura in the displayed images.